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How to go wild

By MARK STANLEY PRICE and IAIN GORDON

THROUGHOUT the world, we are driving species towards extinction at an ever increasing rate. In the early 1960s, zoos began to emphasise their role as arks that might save such endangered species. By breeding animals in captivity and then releasing them in protected reserves, we might rescue some species. Yet well-meaning conservationists often give too little thought to how the animals will fare once they have gone ‘back to nature’. Ecologists now realise, for instance, how much harder it is to survive as an orang-utan than an oryx. Reintroductions of some species, it seems, are fraught with difficulty and may even be doomed to failure.

In the past, many animals have been reintroduced to the wild in an unplanned and haphazard manner. In the 1970s, for example, conservationists returned the nene, the Hawaiian goose, to its native islands after it bred successfully at reserves run by the Wildfowl Trust in Britain. But the release of 1244 birds on Hawaii and 391 on Maui Island over 16 years has failed&colon; the nene has not established a self-sustaining population anywhere in the Hawaiian archipelago. The reintroductions failed for several reasons. The nene spends much time on the ground, and the adults moult when leading their young, and so cannot fly, making both the adults and young vulnerable to hunters, and to predators that people have introduced. Another factor which may have reduced their breeding success was that biologists released most of the geese in the mountains, which the birds originally used for only a short period each year.